Question: Evaluate the definite integral. $\int^6_{1}2\,dx = $
First, use the power rule: $\int^6_{1}2\,dx ~=~2x\Bigg|^6_{1}$ Second, plug in the limits of integration and simplify: $[2\cdot6]-[2\cdot{1}] = 12-2 = 10$. The answer: $\int^6_{1}2\,dx ~=~ 10$